JP2011058386A - Control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a vehicle certainly preventing a sudden reduction in engine speed or stopping of an engine by appropriately controlling engine output when performing in-gear control in the vehicle including a belt continuously variable transmission. <P>SOLUTION: When performing the in-gear control for engaging a clutch 42 from a disengaged stage, control to increase the belt pinching pressure of the CVT 43 is performed. Estimated load torque FTQOP added to the engine 1 by an oil pump 24 is calculated according to a lateral pressure command value FTQPD representing the amount of the belt pinching pressure increased. An in-gear control correction term DICVTOPADD is calculated according to the estimated load torque FTQOP. The target opening THCMD of a throttle valve is corrected in an increasing direction by the in-gear control correction term DICVTOPADD. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a control device for a vehicle driven by an internal combustion engine, and more particularly to a control device for a vehicle in which an output of the internal combustion engine is transmitted to drive wheels via a belt type continuously variable transmission.

  Patent Document 1 discloses a vehicle control device in which an output of an internal combustion engine is transmitted to drive wheels via a belt-type continuously variable transmission. According to this control device, in order to change the gear ratio of the continuously variable transmission to the low speed side when the vehicle is decelerated, control is performed to increase the belt clamping pressure by increasing the driving load of the oil pump driven by the engine. At that time, control for increasing the engine output is performed to prevent the engine from being stopped.

JP 2007-71160 A

  In-gear control for shifting from a state where the engine output is not transmitted to the drive wheels via the belt type continuously variable transmission, more specifically, a clutch provided between the engine and the transmission is disconnected. Also, when performing in-gear control to be fastened from the above state, it is necessary to increase the belt clamping pressure, and it is necessary to increase the driving load of the oil pump. However, Patent Document 1 does not show engine output control when performing in-gear control.

  The present invention has been made paying attention to this point, and appropriately controls the engine output when performing in-gear control in a vehicle equipped with a belt-type continuously variable transmission to ensure a rapid decrease in engine speed or engine stop. An object of the present invention is to provide a vehicle control apparatus that can prevent the above-described problem.

  In order to achieve the above object, an invention according to claim 1 includes an internal combustion engine (1) for driving a vehicle, a clutch (42) and a belt type continuously variable transmission (43), and outputs the output of the engine. A vehicle comprising: a driving force transmission mechanism that transmits to a driving wheel of the vehicle; and an oil pump (24) that is driven by the engine and supplies hydraulic pressure for controlling belt clamping pressure of the continuously variable transmission (43). In the control device, in-gear control determination means for determining that in-gear control for completing the engagement is executed from a state where the clutch (42) is disengaged, and for increasing the belt clamping pressure during execution of the in-gear control. It is characterized by comprising a clamping pressure increasing means and an engine output increasing means for increasing the engine output in accordance with an increase amount (FTQPD) of the belt clamping pressure.

  According to a second aspect of the present invention, in the vehicle control device according to the first aspect, the continuously variable transmission (43) includes a drive pulley (51) and a driven pulley (52), The clamping pressure increasing means increases both the belt clamping pressure of the drive pulley (51) and the belt clamping pressure of the driven pulley (52), and the engine output increasing means is configured to increase the belt clamping pressure command of the drive pulley. The engine output is increased according to the larger one of a value (FTQPDR) and a belt clamping pressure command value (FTQPDN) of the driven pulley.

  According to the first aspect of the present invention, the control for increasing the belt clamping pressure is performed when the in-gear control for completing the engagement is executed from the state where the clutch is disengaged, and according to the increase amount of the belt clamping pressure. The engine output is controlled to increase. Therefore, when the in-gear control is performed, it is possible to prevent a sudden decrease in engine speed or engine stop.

  According to the second aspect of the invention, both the belt clamping pressure of the drive pulley and the belt clamping pressure of the driven pulley are controlled to increase, and the belt clamping command value of the drive pulley and the belt of the driven pulley are controlled. The increase control of the engine output is performed according to the larger increase amount of the clamping pressure command value. By performing control according to the command value of the belt clamping pressure, a delay in control is avoided, and by further increasing the engine output according to the larger belt clamping pressure command value, the engine rotational speed is suddenly decreased or the engine is stopped. It can be surely prevented.

1 is a diagram illustrating a configuration of a vehicle internal combustion engine, an automatic transmission, and a control device thereof according to an embodiment of the present invention. It is a figure which shows the belt-type continuously variable transmission mechanism contained in an automatic transmission, and its control system. It is a flowchart of the process which calculates the shift control correction term (IAT) applied to calculation of the target opening degree (THCMD) of a throttle valve. It is a flowchart of the process performed by the process of FIG. 3, and calculating the estimated load torque (FTQOP) of an oil pump. It is a figure which shows the map referred by the process of FIG.3 and FIG.4. It is a time chart for demonstrating the process of FIG.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a configuration of an internal combustion engine and an automatic transmission that drive a vehicle according to an embodiment of the present invention, and control devices thereof. An internal combustion engine (hereinafter simply referred to as “engine”) 1 has an intake pipe 2, and a throttle valve 3 is disposed in the middle of the intake pipe 2. The throttle valve 3 is provided with a throttle valve opening sensor 4 for detecting the opening TH of the throttle valve 3, and a detection signal thereof is supplied to an electronic control unit (hereinafter referred to as “ECU”) 5. An actuator 7 that drives the throttle valve 3 is connected to the throttle valve 3, and the operation of the actuator 7 is controlled by the ECU 5.

  A fuel injection valve 6 is provided for each cylinder slightly upstream of an intake valve (not shown). Each injection valve is connected to a fuel pump (not shown) and electrically connected to the ECU 5 to receive a signal from the ECU 5. Thus, the valve opening time of the fuel injection valve 6 is controlled.

  The engine 1 is provided with a rotation speed sensor 9 for detecting the engine rotation speed NE and a cooling water temperature sensor 10 for detecting the engine cooling water temperature TW. Detection signals from these sensors are supplied to the ECU 5.

  The ECU 5 includes an accelerator sensor 11 that detects an accelerator pedal depression amount (hereinafter referred to as “accelerator pedal operation amount”) AP of a vehicle driven by the engine 1, and a vehicle speed that detects a vehicle speed VP of the vehicle driven by the engine 1. The sensor 12 is connected, and the detection signal is supplied to the ECU 5.

  The ECU 5 shapes input signal waveforms from various sensors, corrects the voltage level to a predetermined level, converts an analog signal value into a digital signal value, etc., and a central processing circuit (hereinafter referred to as “CPU”). A storage circuit for storing various calculation programs executed by the CPU, calculation results, and the like, and an output circuit for supplying a drive signal to the actuator 7, the fuel injection valve 6, and the like. The ECU 5 controls the valve opening time of the fuel injection valve 6 and the ignition timing based on the detection signal of the sensor described above, calculates the target opening THCMD of the throttle valve 3, and detects the detected throttle valve opening. Throttle valve opening control for driving the actuator 7 is performed so that TH coincides with the target opening THCMD.

  The crankshaft 8 of the engine 1 is connected to an automatic transmission 21, and the automatic transmission 21 is controlled by the ECU 5 via a hydraulic control unit 23. The automatic transmission 21 has an output shaft 22 that drives the driving wheels of the vehicle via a power transmission mechanism (not shown). An oil pump 24 driven by the engine 1 is provided, and shift control of the automatic transmission 21 is performed using the discharge hydraulic pressure of the oil pump 24.

  The automatic transmission 21 includes a torque converter 41 connected to the crankshaft 8, a clutch 42 connected to the output shaft of the torque converter 41, and a belt type continuously variable transmission mechanism (hereinafter “ CVT) 43).

A shift lever switch 31 is connected to the ECU 5, and a switching signal for the shift lever switch 31 is supplied to the ECU 5. The shift lever switch 31 is a shift lever among a D range that automatically controls the gear ratio of the CVT 43 to an optimum value, an R range that is used when moving backward, an N range that selects a neutral position, a P range that is used when parking, etc. A signal indicating the range selected by (not shown) is output.
The ECU 5 performs automatic shift control based on the accelerator pedal operation amount AP, the vehicle speed VP, the engine speed NE, and the like, in addition to the engine control described above.

  In the present embodiment, the in-gear control is executed in a period from when the engagement of the clutch 42 is commanded in a state where the clutch 42 is disconnected until the engagement is completed. In other words, the in-gear control is performed during the period from when the shift lever position is changed from the N range or P range (non-traveling range) to the D range or R range (traveling range) until the engagement of the clutch 42 is completed. Executed.

The ECU 5 calculates the target opening THCMD of the throttle valve by the following formula (1). THCB in equation (1) is a basic target opening calculated according to the accelerator pedal operation amount AP, and THFB is calculated so that the engine speed NE matches the target speed NOBJ when the engine 1 is in an idle state. The IAT is a shift control correction term calculated by the processing of FIG. 3 and is set to increase the engine output when the in-gear control is executed. Although other correction terms are also applied to the calculation of the target opening degree THCMD, it is not directly related to the present invention and is therefore included in the basic target opening degree THCB.
THCMD = THCB + THB + IAT (1)

  As shown in FIG. 2, the CVT 43 includes a drive pulley 51, a driven pulley 52, and a belt 53 that transmits the drive torque of the drive pulley 51 to the driven pulley 52. A first electromagnetic valve 61 for controlling the belt clamping pressure of the drive pulley 51 and a second electromagnetic valve 62 for controlling the belt clamping pressure of the driven pulley 52 are provided. The ECU 5 controls the belt clamping pressure of the pulleys 51 and 52 by changing the opening degree of the first and second electromagnetic valves 61 and 62. When the belt clamping pressure of the pulleys 51 and 52 is increased, the driving load of the oil pump 24 applied to the engine 1 increases.

FIG. 3 is a flowchart of a process for calculating the shift control correction term IAT, and this process is executed by the CPU of the ECU 5 every predetermined time.
In step S11, it is determined whether or not the non-traveling range flag FATNP is “1”. The non-traveling range flag FATNP is set to “1” when the N range or the P range is selected. If the answer to step S11 is affirmative (YES), the downcount timer TICVTNP is set to a predetermined time TMICVTNP (for example, 5 seconds) and started (step S12), and the post-startup correction term DIASTATF and the shift control correction term IAT are set. “0” is set (step S13). The post-startup correction term DIAASTF is a correction term for performing a rotational speed increase control for increasing the engine rotational speed at the time of idling immediately after the engine is started, and is set to a predetermined value immediately after the start. It is gradually reduced to “0”.

  If the answer to step S11 is negative (NO), that is, if the travel range is selected, the basic correction term IATTMP is calculated according to the target idle speed NOBJ and the engine coolant temperature TW (step S14). In step S15, a post-startup correction term DIAASTF is calculated. That is, the post-startup correction term DIAASTF is set to a predetermined value during the rotation speed increase control immediately after the start, and gradually decreases until reaching “0” after the rotation speed increase control is completed.

  In step S16, it is determined whether or not the value of the timer TICVTNP started in step S12 is “0”. Since this answer is negative (NO) at first, the process proceeds to step S17 to determine whether or not the vehicle speed VP is equal to or higher than a predetermined vehicle speed VATNPIN (for example, 3 km / h). If this answer is negative (NO) and the vehicle is almost stopped, it is determined whether or not the transient state flag FTQADSB is "1" (step S18). The transient state flag FTQADSB is set to “1” when the shift lever position is changed from the non-traveling range to the traveling range, and when a predetermined time T2 (for example, 0.5 seconds) has elapsed since the completion of the in-gear control, or It is returned to “0” at a later point of time when a predetermined time T3 (a time longer than the predetermined time T2, for example, 1 second) has elapsed since the start of in-gear control.

  Immediately after the shift lever position is changed from the non-traveling range to the traveling range, the process proceeds from step S18 to step S19, where the FTQOP calculation process shown in FIG. 4 is executed and the estimation applied to the engine 1 to drive the oil pump 24 A load torque FTQOP is calculated.

  In step S31 of FIG. 4, the belt clamping pressure command value (hereinafter referred to as “drive side pressure command value”) FTQPDR of the drive pulley 51 of the CVT 43 is converted into the belt clamping pressure command value (hereinafter referred to as “driven side pressure command”) of the driven pulley 52. It is determined whether or not it is smaller than FTQPDN. If this answer is affirmative (YES), the side pressure command value FTQPD is set to the driven side pressure command value FTQPDN (step S32). On the other hand, when FTQPDR ≧ FTQPDN, the side pressure command value FTQPD is set to the drive side pressure command value FTQPDR (step S33). That is, the side pressure command value FTQPD is set to the larger one of the driven side pressure command value FTQPDN and the drive side pressure command value FTQPDR.

  In step S34, an FTQOP map shown in FIG. 5A is retrieved according to the side pressure command value FTQPD and the target rotational speed NOBJ, and an estimated load torque FTQOP is calculated. The solid line shown in FIG. 5A corresponds to the first predetermined rotation speed NEH (for example, 1100 rpm), and the broken line corresponds to the second predetermined rotation speed NEL (for example, 600 rpm). The FTQOP map is set so that the estimated load torque FTQOP increases as the side pressure command value FTQPD increases.

  Returning to FIG. 3, in step S20, the DICVTOPADD map shown in FIG. 5B is searched according to the estimated load torque FTQOP and the target rotational speed NOBJ, and the in-gear control correction term DICVTOPADD is calculated. The solid line shown in FIG. 5B corresponds to the first predetermined rotation speed NEH, and the broken line corresponds to the second predetermined rotation speed NEL. The DICVTOPADD map is set so that the in-gear control correction term DICVTOPADD increases as the estimated load torque FTQOP increases.

On the other hand, if the answer to step S18 is negative (NO), that is, if the transient state flag FTQADSB is "0", the process proceeds to step S21, and the in-gear control correction term DICVTOPADD is updated by the following equation (2). DDICVT in Expression (2) is a predetermined subtraction value. By repeating the calculation of Expression (2), the in-gear control correction term DICVTOPADD gradually decreases. When the calculation result of Expression (2) becomes a negative value, the in-gear control correction term DICVTOPADD is set to “0”.
DICVTOPADD = DICVTOPADD−DDICVT (2)

In step S23, the basic correction term IATTMP, the post-startup correction term DIASTATF, and the in-gear control correction term DICVTOPADD are applied to the following equation (3) to calculate the shift control correction term IAT.
IAT = IATTMP + DIATASTF + DICVTOPADD (3)

  When the vehicle speed VP becomes equal to or higher than the predetermined vehicle speed VATNPIN or when the predetermined time TMICVTNP has elapsed from the time of switching to the travel range, the process proceeds from step S17 or S16 to step S22, and the in-gear control correction term DICVTOPADD is set to “0”. To do.

  FIG. 6 is a time chart for explaining the above-described in-gear control, and shows transitions of the non-traveling range flag FATNP, the transient state flag FTQADSB, the estimated load torque FTQOP, the shift control correction term IAT, and the engine speed NE.

  When the shift lever position is changed to the travel range at time t0, the shift control correction term IAT increases stepwise, and the in-gear control correction term DICVTOPADD is set to a value corresponding to the estimated load torque FTQOP. The in-gear control correction term DICVTOPADD gradually decreases as the estimated load torque FTQOP decreases slightly before time t1, and becomes “0” at time t1 immediately after the transient state flag FTQADSB becomes “0”.

The solid lines in FIGS. 6D and 6E show the transition of the shift control correction term IAT and the engine speed NE in the present embodiment, and the thick broken line shows the shift control correction term IAT when the in-gear control correction term DICVTOPADD is not used. Changes in engine speed NE are shown. In addition, the thin broken line of FIG.6 (e) shows transition of target rotational speed NOBJ.
As is apparent from this figure, by applying the in-gear control correction term DICVTOPADD, it is possible to suppress a decrease in the engine speed NE.

  As described above, in the present embodiment, when in-gear control is performed in which the clutch 42 is engaged from the disconnected state, control for increasing the belt clamping pressure (pulley side pressure) of the CVT 43 is performed, and the belt clamping pressure is reduced. The estimated load torque FTQOP of the oil pump 24 is calculated according to the side pressure command value FTQPD indicating the increase amount, the in-gear control correction term DICVTOPADD is calculated according to the estimated load torque FTQOP, and the target opening of the throttle valve is determined by the in-gear control correction term DICVTOPADD. The degree THCMD is corrected in the increasing direction. Accordingly, when in-gear control is performed, it is possible to prevent a sudden decrease in engine speed NE or an engine stall.

  Further, both the belt clamping pressure of the drive pulley 51 and the belt clamping pressure of the driven pulley 52 are controlled to increase, and either the side pressure command value FTQPDR of the drive pulley 51 or the side pressure command value FTQPDN of the driven pulley 52 is larger. The in-gear control correction term DICVTOPADD is calculated according to the direction. By performing control according to the side pressure command value FTQRDR or FTQPDN, a delay in control is avoided, and by calculating the in-gear control correction term DICVTOPADD according to the larger side pressure command value, the engine speed NE is rapidly decreased or the engine Stalls can be reliably prevented.

  In this embodiment, the throttle valve 3 and the actuator 7 constitute a part of the engine output increasing means, and the ECU 5 constitutes a part of the in-gear control determining means, the clamping pressure increasing means, and the engine output increasing means. Specifically, step S11 in FIG. 3 corresponds to the in-gear control determination means, and steps S18 to S20 and S23 correspond to the engine output increasing means.

  The present invention is not limited to the embodiment described above, and various modifications can be made. For example, in the embodiment described above, engine output control is performed by changing the throttle valve opening TH, but in an engine having a variable lift amount valve mechanism that can continuously change the maximum lift amount of the intake valve. The engine output control may be performed by changing the maximum lift amount of the intake valve. In that case, the variable lift valve operating mechanism constitutes a part of the engine output increasing means.

1 Internal combustion engine 3 Throttle valve (engine output increasing means)
5 Electronic control unit (in-gear control determination means, clamping pressure increasing means, engine output increasing means)
7 Actuator (Engine output increasing means)
21 Automatic transmission 42 Clutch 43 Belt type continuously variable transmission mechanism (belt type continuously variable transmission)

Claims (2)

An internal combustion engine for driving the vehicle; a clutch and a belt type continuously variable transmission; a driving force transmission mechanism for transmitting the output of the engine to drive wheels of the vehicle; and the continuously variable transmission driven by the engine In a vehicle control device comprising an oil pump for supplying hydraulic pressure for controlling the belt clamping pressure of the machine,
In-gear control determining means for determining that in-gear control for completing the engagement from the disengaged state of the clutch is being executed;
Clamping pressure increasing means for increasing the belt clamping pressure during execution of the in-gear control;
An engine output increasing means for increasing the engine output according to an increase amount of the belt clamping pressure is provided.   The continuously variable transmission includes a drive pulley and a driven pulley, and the clamping pressure increasing means increases both the belt clamping pressure of the drive pulley and the belt clamping pressure of the driven pulley. The output increasing means increases the engine output according to a larger one of a belt clamping pressure command value of the drive pulley and a belt clamping pressure command value of the driven pulley. The vehicle control device described.

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